MN10300: Make the boot wrapper able to use writeback caching

Make the boot wrapper able to use writeback caching, including flushing the
cache before jumping to the main kernel.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 48 insertions, 1 deletions

diff --git a/arch/mn10300/boot/compressed/head.S b/arch/mn10300/boot/compressed/head.S
index 502e1eb5670..4ef608a6241 100644
--- a/arch/mn10300/boot/compressed/head.S
+++ b/arch/mn10300/boot/compressed/head.S
@@ -14,6 +14,7 @@
 
 #include <linux/linkage.h>
 #include <asm/cpu-regs.h>
+#include <asm/cache.h>
 
         .globl startup_32
 startup_32:
@@ -37,8 +38,15 @@ startup_32:
         mov     (a0),d0
         btst    CHCTR_ICBUSY|CHCTR_DCBUSY,d0            # wait till not busy
         lne
-        mov     CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD,d0   # writethru dcache
+
+#ifdef CONFIG_MN10300_CACHE_ENABLED
+#ifdef CONFIG_MN10300_CACHE_WBACK
+        mov     CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRBACK,d0
+#else
+        mov     CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRTHROUGH,d0
+#endif /* WBACK */
         movhu   d0,(a0)                                 # enable
+#endif /* !ENABLED */
 
         # clear the BSS area
         mov     __bss_start,a0
@@ -54,6 +62,9 @@ bssclear_end:
 
         # decompress the kernel
         call    decompress_kernel[],0
+#ifdef CONFIG_MN10300_CACHE_WBACK
+        call    mn10300_dcache_flush_inv[],0
+#endif
 
         # disable caches again
         mov     CHCTR,a0
@@ -69,10 +80,46 @@ bssclear_end:
         mov     (4,a0),d1
         mov     (8,a0),d2
 
+        # jump to the kernel proper entry point
         mov     a3,sp
         mov     CONFIG_KERNEL_TEXT_ADDRESS,a0
         jmp     (a0)
 
+
+###############################################################################
+#
+# Cache flush routines
+#
+###############################################################################
+#ifdef CONFIG_MN10300_CACHE_WBACK
+mn10300_dcache_flush_inv:
+        movhu   (CHCTR),d0
+        btst    CHCTR_DCEN,d0
+        beq     mn10300_dcache_flush_inv_end
+
+        mov     L1_CACHE_NENTRIES,d1
+        clr     a1
+
+mn10300_dcache_flush_inv_loop:
+        mov     (DCACHE_PURGE_WAY0(0),a1),d0    # unconditional purge
+        mov     (DCACHE_PURGE_WAY1(0),a1),d0    # unconditional purge
+        mov     (DCACHE_PURGE_WAY2(0),a1),d0    # unconditional purge
+        mov     (DCACHE_PURGE_WAY3(0),a1),d0    # unconditional purge
+
+        add     L1_CACHE_BYTES,a1
+        add     -1,d1
+        bne     mn10300_dcache_flush_inv_loop
+
+mn10300_dcache_flush_inv_end:
+        ret     [],0
+#endif /* CONFIG_MN10300_CACHE_WBACK */
+
+
+###############################################################################
+#
+# Data areas
+#
+###############################################################################
         .data
         .align          4
 param_save_area: